In order to detect and track purloined, in particular, stolen vehicles (e.g., passenger cars and trucks, ships or airplanes), detecting and tracking devices are used that are able to report the momentarily determined global position of a vehicle via distance communication connection, for example by means of a mobile radio system such as GSM (Global System for Mobile Communication), to a detecting and tracking service.
The detecting and tracking devices predominantly use satellite navigation systems GNSS (Global Navigation Satellite System), such as the globally available GPS (Global Positioning System), for determining the global position. In the future, it will also be possible to use the European satellite navigation system GALILEO for this purpose. The momentarily determined global position of a vehicle can be transmitted either on request of the detecting and tracking service or automatically upon a certain event, for example the activation of an alarm system in the vehicle, from a detecting or tracking device to the service.
In order to prevent the detection of the vehicle, so-called jammers such as, for example, GPS jammers are increasingly used. Jammers are interfering transmitters that prevent the reception of navigation signals of a satellite navigation system from detection. Jammers can also be designed such that not only the reception of navigation signals, but also of mobile radio signals is disturbed so that a detecting and tracking device cannot receive mobile radio signals from a detecting and tracking service and, for example, cannot receive requests for information about the actual position transmitted via mobile radio from such services.
Alternatively, it is also possible to use spoofing transmitters in order to prevent accurate vehicle detection. Spoofing transmitters interfere with the detection by transmitting falsified imitated navigation signals. GPS spoofing transmitter generate GPS signals with formally valid but wrong position data. Usually, spoofing is more complicated than jamming because generating falsified navigation signals currently requires a high level of technical effort.
Jammers and spoofing transmitters are generally designated here as interfering transmitters.
Exemplary embodiments of the present invention are directed to improvements in devices for detecting and tracking vehicles that use satellite navigation.
In accordance with exemplary embodiments of the present invention, a device provided for detecting and tracking vehicles, which is in particular based on satellite navigation, is extended in such a manner that the device itself is able to detect an interfering transmitter such as an activated jammer and/or a spoofing transmitter. For detecting an interfering transmitter causing jamming and/or spoofing, according to the invention, one or a plurality of different measures can be used alternatively or in some cases also combined:                a receiver used in a position-determining device for position-determining signals such as navigation signals of a satellite navigation system, for example, can monitor one or a plurality of receive parameters of received position-determining signals in order to detect an interfering transmitter that influences these parameters;        the receiver for position-determining signals can also detect an interfering transmitter due to the fact that the receiver is not able to perform a position determination for a predetermined time period because this is an indication of the use of an interfering jamming transmitter;        measurements of the receiver for position-determining signals can also be checked for consistency, in particular in the case of navigation signals of a satellite navigation system using known integrity monitoring technologies such as RAIM (Receiver Autonomous Integrity Monitoring) through which signals of interfering spoofing transmitters can be identified;        measurements of the receiver for position-determining signals can also be compared with measurements of other sensors such as a distance meter or a speedometer in order to be able to identify significant deviations which indicate the use of an interfering spoofing transmitter;        finally, it is also possible to use a device (jammer/spoofing detector) suitable specifically for detecting jammers and/or spoofing transmitters.        
The invention has the advantage that despite the use of interfering transmitters, detecting a stolen vehicle is possible in most situations. Furthermore, when detecting an interfering transmitter, the invention enables initiation of further measures that make it difficult to steal a vehicle or even can prevent it. Detection of an active interfering transmitter, in particular of a jammer or spoofing transmitter, according to the invention improves detection and tracking of vehicles in different ways. For example, a vehicle detecting and tracking service can be informed about the detection of the interfering transmitter, in particular by means of a mobile radio connection, since interfering transmitters usually can only interfere with receiving but not with transmitting radio signals. Also, a detected interfering transmitter can trigger a certain action, for example blocking a stolen vehicle, switching to another communication channel for receiving signals for the detection, or considering an alternative detection method, for example by means of mobile radio.
One exemplary embodiment of the invention relates to a detecting and tracking device for vehicles comprising a position-determining device for determining a current vehicle position, a transmitting device for transmitting the current vehicle position via a communication channel to a receiver, and means for detecting an activated interfering transmitter and for triggering an action depending on the detection of an activated interfering transmitter.
The means for detecting an activated interfering transmitter can have a receiver for position-determining signals, in particular navigation signals, integrated in the position-determining device, wherein the receiver is configured for monitoring one or a plurality of received position-determining signals in order to detect an interfering transmitter influencing these parameters. For example, one or a plurality of receiver-internal measured values of navigation signals, for example GPS signals, which are relevant for tracking and/or capturing navigation signals, can be monitored such as the receive signal strength, the carrier-to-noise density ratio, the statistical distribution of samples or other measured values provided by a front end of the receiver. Since mainly jamming influences such measured values, it is possible to detect in particular jamming transmitters.
The means for detecting an activated interfering transmitter can also have a receiver for position-determining signals, in particular navigation signals of a satellite navigation system, which receiver is integrated in the position-determining device, wherein the receiver is configured for detecting an interfering transmitter due to the fact that during a predetermined time period, the receiver cannot perform a position determination. Because jamming transmitters interfere with the reception of navigation signals to such a great extent that during active jamming, no position determination is possible, it is therefore possible to detect mainly jamming transmitters.
The means for detecting an activated interfering transmitter can further comprise a receiver for position-determining signals, in particular navigation signals of a satellite navigation system, which receiver is integrated in the position-determining device, wherein the receiver is configured for checking measurements of position-determining signals for consistency, in particular by using a RAIM (Receiver Autonomous Integrity Monitoring) technology. With RAIM technologies it is possible to check received navigation signals for integrity, to detect wrong navigation signals and to exclude them from position determination. This technology is therefore particularly well suited for detecting spoofing transmitters. However, it is also suitable for detecting jamming transmitters when, for example, navigation signals are received which are disturbed and, in particular, falsified by jamming.
The means for detecting an activated interfering transmitter can also comprise a receiver for position-determining signals, in particular navigation signals of a satellite navigation system, which receiver is integrated in the position-determining device, wherein the receiver is configured for comparing measurements of position-determining signals with measurements of other sensors, in particular a distance meter and/or a speedometer in order to be able to identify significant deviations which indicate the use of an interfering transmitter, in particular of a spoofing transmitter. If, for example, a significant deviation of a vehicle speed determined with a speedometer from the vehicle speed determined by means of navigation signals, in particular GPS signals, occurs, this can be an indication of a spoofing transmitter which transmits falsified navigation signals.
The means for detecting an activated interfering transmitter can also comprise a device specifically suited for detecting interfering transmitters, for example a jamming/spoofing detector.
The means for triggering an action depending on the detection of an activated interfering transmitter can be configured for transmitting with the transmitting device a message about a detected interfering transmitter via the communication channel, in particular a mobile radio channel. For example, the message can be used for determining an approximate current position of a vehicle, for example with one of the known methods used in mobile radio systems for determining the position of mobile radio subscribers. The message can also include data about the current vehicle position which has been determined in a different manner, for example via a distance measurement or detection via mobile radio signals.
The means for triggering an action depending on the detection of an activated interfering transmitter can also be configured for initiating a vehicle blockage. For example, an immobilizer can be activated when an interfering transmitter has been detected, or the engine of the vehicle can be turned off and the engine control can be deactivated.
The means for triggering an action depending on the detection of an activated interfering transmitter can further be configured for requesting authentication for releasing the vehicle blockage. For example, after a vehicle blockage due to a detected interfering transmitter, a message that the vehicle is blocked and that entering a code is required for releasing the blockage can be displayed on a display device of the vehicle.
Furthermore, one embodiment of the invention relates to the use of a device according to the invention and as described above in an object, in particular a vehicle, for detecting and tracking the object. Although the device according to the invention is described above in connection with detecting and tracking a vehicle, the device is principally suited for detecting and tracking any movable objects such as, for example, containers for storing and transporting goods. In the case of a container, it is possible, for example, to activate instead of a vehicle blockage, an additional safety measure in order to make it difficult to open the container.
Further advantages and possibilities of use of the present invention arise from the following description in connection with the exemplary embodiments illustrated in the drawings.
In the description, in the claims and in the abstract, the terms and associated reference numbers listed in the reference list below are used.